Technical Field
The present invention relates to optical devices, and more particularly to optical device integration using an underfill material to eliminate losses between a photonics device and an optical component.
Description of the Related Art
An optical multi-chip module (MCM) includes optical waveguides on an organic substrate where optical devices such as vertical cavity surface emitting laser (VCSEL) or photodiode (PD) chips are mounted. The light from/to the device is coupled with the optical waveguides via 45-degree mirrors, where total internal reflection (TIR) mirrors manufactured by laser ablation techniques are employed for high channel density applications.
The VCSEL/PD chips are encapsulated by an underfill when placed on the organic substrate. During production, the underfill material enters mirror cavities located on a same side as the chips so that the TIR mirrors do not function properly. Loss can also be caused by an inclination of the VCSEL/PD chips when electrodes are located slightly off a chip center and cannot be well-controlled when they are mounted.